WGS 84

Overview The World Geodetic System 1984 (WGS 84) is the reference coordinate system used by the Global Positioning System (GPSGPSThe Global Positioning System (GPS) is a satellite-based navigation system operated by the U.S. Space Force that prov...) and serves as the foundational datumDatumA geodetic datum is a mathematical model that defines the size, shape, and orientation of the Earth, serving as the r... for the majority of global mapping and geospatial applications. Maintained by the United States National Geospatial-Intelligence Agency (NGA), WGS 84 defines an Earth-centered, Earth-fixed coordinate system along with an associated reference ellipsoidReference EllipsoidA reference ellipsoid is a mathematically defined surface that approximates the shape of the Earth as an oblate spher..., geoidGeoidThe geoid is the equipotential surface of Earth's gravity field that best approximates global mean sea level. It serv... model, and gravitational model that together enable precise positioning anywhere on the planet.

WGS 84 is built upon the GRS 80 ellipsoid with a semi-major axis of 6,378,137 meters and a flattening of 1/298.257223563. The coordinate system origin is at the Earth's center of mass, with the Z-axis aligned to the IERS Reference Pole and the X-axis passing through the IERS Reference Meridian. Positions are expressed as geodetic latitude, longitude, and ellipsoidal height. The associated geoidGeoidThe geoid is the equipotential surface of Earth's gravity field that best approximates global mean sea level. It serv... model (EGM2008) provides the relationship between ellipsoidal heights and orthometric heights referenced to mean sea level. WGS 84 is periodically refined through new realizations that incorporate updated satellite observations.

WGS 84 is the mandatory coordinate system for GPSGPSThe Global Positioning System (GPS) is a satellite-based navigation system operated by the U.S. Space Force that prov... receivers and serves as the default CRS for most web mapping platforms, including Google Maps and OpenStreetMapOpenStreetMapOpenStreetMap (OSM) is a collaborative, open-source mapping project that creates a free, editable map of the world. B.... Aviation and maritime navigation standards require WGS 84 coordinates for flight plans, charts, and automatic identification systems. The GeoJSONGeoJSONGeoJSON is an open standard format for encoding geographic data structures using JavaScript Object Notation (JSON). I... specification mandates WGS 84 (EPSG:4326) for all coordinate data. International data exchange protocols and spatial data infrastructures typically specify WGS 84 as the common reference frame for interoperability.

WGS 84 is functionally equivalent to the International Terrestrial Reference Frame (ITRF) at the centimeter level and closely aligned with NAD 83NAD 83NAD 83 (North American Datum of 1983) is the horizontal geodetic datum used for surveying, mapping, and navigation ac... in North America, though small differences exist due to differing realization epochs. For most practical GISGISGeographic Information Systems (GIS) enable users to analyze and visualize spatial data to uncover patterns, relation... applications, WGS 84 and NAD 83 coordinates are interchangeable, but high-precision surveying and geodetic work requires explicit datumDatumA geodetic datum is a mathematical model that defines the size, shape, and orientation of the Earth, serving as the r... transformations.